Electric circuit breaker



Spt. 7, 1954 R. "r. CASEY 2,688,675

ELECTRIC CIRCUIT BREAKER Filed July 20. 1955 4 57 h 15 34 32 7 Tififli I Robert T. Casey r -IIil b m -.4 77 0/? /'6 14 Z5 31 32 24 8 His Attorney H Invntor Patented Sept. 7, 1954 ELECTRIC CIRCUIT BREAKER Robert T. Casey, Bristol, Conn., assignor to General Electric Company, a corporation of New York Application July 20, 1953, Serial No. 369,173

10 Claims. 1 The present invention relates to improved circuit breakers of the type which may be manually operated to either open or closed position and automatically operated in response to an overload in the circuit in which it is connected.

Electric circuit breakers of the general type described above have been extensively used in industrial applications and in recent years their application to household circuits has increased the need for simpler and less expensive mecha nisms. The present invention involves the elimination of many of the parts found in the operating mechanism of breakers of this type while retaining all of the operating characteristics including manual opening and closing with a snap action, overload tripping and trip free operation.

The objects and advantages that characterize my invention will become more apparent as the following description proceeds, reference being had to the accompanying drawing, and its scope will be pointed out in the appended claims. In the drawing,

Fig. 1 is a side view of one of the parts of the housing and showing the improved breaker mechanism in side elevation in the open circuit position.

Fig. 2 is a similar view showing the parts of the breaker in the closed circuit position.

Fig. 3 is a view similar to Fig. l but showing the parts in the open circuit position after having been automatically actuated by an overload.

Fig. 4 is a perspective view of a housing for the improved breaker mechanism and showing the operating lever in the position it occupies when the parts are in the closed circuit position.

Fig. 5 is a cross-sectional view on the plane of the line 55 of Fig. 1.

In the form shown, the housing consists of the separable parts i and 8 formed of insulating material and connected together by screws or rivets 9. The circuit terminals [0 and H are arranged at opposite edges of the housing. A stationary Contact 52 is mounted on the terminal ill and the movable contact 13 is formed as a part of or attached to a switch member M. This switch member carries a pivot it which is positioned in elongated inclined grooves it which are preferably rmed in the side walls of the housing.

switch member is preferably U-shaped having two side arms 94, i4 and preferably the pivot pin it extends through said two side arms and is slidably guided in the slots or grooves it in the two side walls of the housing.

A bimetal member I! is secured and connected at one end to the terminal H and its other free end is provided with a latch member 18 which holds the pivot pin [5 in position near the upper ends of the grooves H5. The tip of the switch member is connected by a flexible conductor I9 to the tip of the bimetal member ll. An actuating handle or lever 20 is pivoted at 2| between the two side walls of the housing. The movement of the actuating lever from side to side is limited by the spaced abutments 22 and 23 on one wall of the housing.

The actuating lever 20 is provided with a gooseneck or C-shaped extension 24 which is connected by a rod-like member 25 to the switch member 44. One end of the rod is pivoted at 26 to the end of the gooseneck 24 and the other end is guided in a hinged plate 21 between the two side arms l4, 44 of the switch member. On this rod 25 is a compression spring 28 which is seated on the head 29 of the rod and on the hinged plate 21.

In the position shown in Fig. 1, the spring 28 presses the lower end of the switch member laterally against an abutment 30 on the housing wall and presses upwardly against the tip of the gooseneclc 24 so that the lever 20 is pressed against the shoulder 23 of the housing.

To manually move the contact I 3 from the open position of Fig. 1 to the closed position of Fig. 2, the lever 20 is manually moved to the right thus swinging the pivot pin 26 toward the left and compressing the spring 28 until the pivot 26 passes the center line between the hinge 2 and the pivot 15 whereupon the spring throws the switch arm 14 to the right to the closed circuit or contact position of Fig. 2 with a snap action.

To manually open the circuit from the closed position of Fig. 2, the actuating lever 20 is moved to the left so that the pivot point 26 will be carried by the gooseneck extension 24 to the right of the line of centers between pivot l5 and the hinge 2i whereupon the switch member will be thrown by spring 28 with a snap action to the open circuit position of Fig. 1.

When the circuit is closed as in Fig. 2 and an overload occurs, the bimetal strip ll warps and pulls the latch i 8 away from the pin 15. The spring 28 being under compression and pushing up against the pivot 26, which is stationary for the moment, and down against the hinged connection 2i, forces the switch member and pin [5 downwardly, until pin l5 passes across the line of centers of hinged plate 21 and pin 25, whereupon it reverses its rotational bias on switch member l4 and throws switch member [4 back against the stop 30 as shown in Fig. 3.

In Fig. 3 the handle 20 is shown in dotted lines as retained in the on position while the mechanism has moved to tripped position. The dotted line through the pivot point of hinged plate 27 and pivot 26 shows that the spring 28 will move the handle 20 to a mid position as shown in full lines of Fig. 3 when it is released and will therefore indicate the tripped condition of the breaker.

To manually reset the switch after automatic tripping, the actuating lever is moved to the left from the position of Fig. 3 whereupon the pin or projection 3| carried by the actuating lever will engage the lugs 32 on the switch member forcing the upper end of the switch member to move upwardly and to the right, the pin l sliding upwardly along the grooves l6, and snapping over the latch is on the bimetal strip I l as in Fig. 1, and the actuating lever is moved to the position of Fig. 1.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and that it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A circuit breaker comprising a stationary contact, a movable switch member having a pivot pin at one end and a contact to engage the stationary contact, means supporting and guiding said pivot pin for sliding movement, an overload actuated latch normally preventing sliding movement of said pivot pin, an actuating lever having a gooseneck extension, a toggle member hinged to said extension of said lever and having a sliding connection with said switch member, and a spring compressed between said lever and said switch member for throwing them from a closed circuit position to an open circuit position when said lever is actuated.

2. A circuit breaker comprising a stationary contact, a spring biased switch member having a pivot pin at one end and a contact, means for guiding said pivot pin for sliding movement, an overload actuated latch normally preventing sliding movement of said pivot pin,

a pivoted actuating lever having an extension, a toggle member having a guide rod hinged to said extension and having a sliding and pivoted connection with said switch member between its ends, and a spring interposed between said extension and said switch member.

3. In an electric circuit breaker, a housing, a stationary contact mounted in said housing, a switch member having a pivot pin at one end and a contact at its opposite end, said housing having grooves for supporting and. guiding said pivot pin, an overload actuated latch normally preventing sliding movement of said pivot pin in said grooves, an actuating lever pivoted in said housing and having an extension in said housing, said lever extension and said switch member having coacting parts for returning them from an open circuit position to a closed circuit position and including a spring and toggle member hinged to said extension of said lever and having a sliding and pivotal connection with said switch member.

4. In an electric circuit breaker, a housing, a stationary contact mounted in said housing, a switch member having a pivot pin at one end and a contact at its opposite end, said housing having grooves for guiding said pivot pin, an overload actuated latch normally preventing sliding movement of said pivot pin in said grooves, an actuating lever pivoted in said housing having an extension in said housing, said lever extension and said switch member having coacting parts for returning them to normal closed position including a spring and toggle member hinged to the extension of said lever and having a sliding and pivotal connection with said switch member between its ends.

5. An electric circuit breaker comprising a housing, a stationary contact mounted in said housing, a switch member having a pivot pin at one end and a contact to engage the stationary contact, said housing having grooves for guiding said pivot pin, an overload actuated latch normally preventing sliding movement of said pivot pin in said grooves, an actuating lever pivoted in said housing having a gooseneck extension in said housing, a toggle member hinged to the extension of said lever and having a sliding connection with said switch member, and a spring compressed between said lever extension and said toggle member for returning the parts to normal closed position when said lever is actuated.

6. An electric circuit breaker comprising a housing, a stationary contact mounted in said housing, a spring-biased switch member having a pivot pin at one end and a contact at the other end, said housing having grooves for guidingsaid pivot pin, an overload actuated latch normally preventing sliding movement of said pivot pin in said grooves, an actuating lever pivoted in said housing and having an extension in said housing, a toggle member having a guide rod hinged to the extension of said lever and having a sliding and pivoted connection with said switch member between its ends, a spring interposed between said extension and said pivoted connection, and means on said lever for transmitting pressure to relatch said switch member with said latch.

7. In an electric circuit breaker, a housing, a stationary contact mounted in the housing, a movable switch member having a contact at one end, the opposite end of said switch member having a slidable pivot pin, an elongated guide for said pivot pin, a member having a latch normally preventing said pivot pin from sliding in said guide, means for releasing said pin upon an overload in the circuit of said circuit breaker, a pivoted actuating lever, and a toggle-acting rod and spring hinged to said lever and having a driving connection with said switch member.

8. In an electric circuit breaker, a housing, a stationary contact in the housing, a switch member having a contact at one end coacting with said stationary contact, the opposite end of said switch member having a pivot pin, a guide groove in said housing for said pivot pin, a bimetal member having a latch normally preventing said pivot pin from sliding in said groove, a pivoted actuating lever, a toggle-acting rod hinged to said lever and having a sliding connection with said switch member and a throwing spring on said rod compressed between said lever and said sliding connection.

9. In a circuit breaker, a housing, a stationary contact in said housing, a movable switch member having a contact for coacting with the stationary contact, a pivot pin carried by said switch member, an elongated guide for said pivot pin, an

overload actuated latch normally releasably restraining the movement of said pin along said guide, an actuating lever pivoted in said housing and having a gooseneck extension in said housing, a spring actuated toggle action means interposed between said extension and said switch member for snapping the switch member from the on to the off position and vice versa, said means including a spring and a guide rod conneeting said extension and said switch member, said toggle action means opening the circuit automatically when said latch is released from said pin.

10. In a circiut breaker, a housing, a stationary contact in said housing, a movable switch member having a contact for coacting with the stationary contact, a pivot pin carried by said switch member, an elongated guide for said pivot pin, an overload actuated latch normally releasably restraining the movement of said pin 6 along said guide, an actuating lever pivoted in said housing and having an extension in said housing, a spring actuated toggle action means interposed between said extension and said switch member for snapping the switch member from the on to the off position and vice versa, the toggle action means opening the circuit automatically when said latch is released from said pin, said actuating lever and said switch memher having interacting parts by which the actuating lever and its extension may reset the switch member to the normal off position with the pivot pin restrained by said latch.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,418,359 Link Apr. 1, 1947 2,504,793 Baxter Apr. 18, 1950 

